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cmguafgwpm. Arnauus FoR ExPosmG cxri-mfocmrn POSITIVE mms. AFPUCATIOR FILED )UNIL-19H3,

1 ,310,337. Patented July 15, 1919.

'i Y* 2 SHEETS-SHEIT l.

'Hmmm C. M. HEPWORIH.

APPARATUS FOR EXPUSING CINEMATUGRAPH POSITIVE FILMS.

` APPLIcMlon ruso IuNs s. ma

1,310,337. Patented July 15, 1919.

2 SHiETS-*SHEET 2.

UNITED STATES PATENT oEEIoE..l

onen. MILTON nnrwon'rn, or Lennon, ENGLAND.

APPARATUS FOB EXPOSING CINEMATOGRAPH IEQSITIVEl FILMS.

To all whom it may concern: y' l Be it known ,that I, Cecil. MxL'mN HEP- ivon'rll, a subject of the King of-England, residing in London,` England, have invented Xx-tain newf'andruseflrl Im rovements iln mratus or 4x sin inemato i 1 Psa-iitive Films, of iiiich gthe follovv'inlrilsl a. specification.) j

This invention is for improvements in or relating to apparatus for exposing cinematograph positive films and has forA its object to provide means whereby the positive film can be more readil made of equal intensity throughout than xs possiblev with present methods of exposure. l

*As is" well-known, the negative film consists of strips whose degre of intensity "aries and heretofore this strip has been pro vided with notches along one side which operatea switch to vary the itensity of the light whereby the exposure of the positive is being made so that more light is available for-those sections receiving the impression i from adensepart of the negative than is available for those portions which are receiving impressions from a less dense portion of the negative.` `With present methods, 10 degrees of light intensity are employed and it has only been possible to set the apparatus for, say, 10 changes. so that after 10 sections of strip each requiring a change has been operated upon, the yapparatus had to be again set before the exposure could be proceeded with. ,U v,

The object of the present invention is to enable as many changes to be made asis re- -quired for the whole length of the strip, without any re-setting of the apparatus, the ap aratus in fact being sel f-setting. i

ccording to this invention, there is eombined with a source of light and a rotatable electric circuit-selector to control that light,

which selector is itself controlled by means operated by the negative film. a stop for the said selector, means for automatically ad- 'vancing the stop intermittently, and means opel-atively-connected to the selector by Aone edge oi the` film, -and the advance v{ },fthe

selector controlled by other"contact'dev1ees ooperating with notches or slots at or near the other edge of the film.

In the accompanying drawings which illustrate one method of carrying out, this invention Figure 1 is a perspective viewv of the selector and stop-mechanism with partsbroken away forthesake ofclearness;`

vFig.: a perspective view `ofV the main ,operative parts shown a ltilifi'erelnt yposition; "3. A

Fig. 3 is a diagram illustratinga portion of the negative fihn and the contact-devices -for coperation therewith; .p

F ig. 4 is a portion OffiImcOnStrUcted for coperation withfa4V different, forni Aof contattjdevice, I." .i

ig. o 1s a ers 4 Fig. 6, is a diagram showing theV electri ral connections for the magnets.

The same letters indicate thc same parts tl1rougl\out,thc drawingsl;

(')n the baseA, su )ports are provided for a shafty B. Oneof tlie supports is shown at Bl'in Figi'. l and the other'supportf-at B2 iu ,Fig 2. linligp 1, the support- B2 has been removed *front the recesrnli34 in the, baseplatcri,` f i Fast on the shaft B is a toothed disk C. Ar. the side of the disk isa sleeve C* which is; conccntrically disposed tn the shaft li. The sleeve at one cnd incloses one cud of a spiral springllivhich surrounds the` shaft B and atjthe `othcrend is slotted at C. and projecting into the slot is a pin C.\vhvh iS fast 'on the shaft f j y i One end of the sprimgr D is secured to the sleeve. C" as indicated at D and the other end is madefastat Dito a secondtoothcd disk E which is mounted free on thi` shaft B. The sleeve G1 has a projecting finger C* at that cud which is near thv disk E. and tht` disk i provided with a projection which lit-s in the path of this fingen C.

ctive iiew" rof the.' sleeve Patented yJuly 15, i919.v applieauonmeuune 5.19m. srmi'no.ess';sf1sj i A spiral spring C is Secured at one end to the sleeve C1 by a screw C and at the other end to the disk C by a screw C7. I

The disk E has a sleeye E2 from which projects selector-arm E. The selector arm sweeps over the contacts F of a rheostat, the resistances of which are shown at F.

At one end of the shaft a pulley G is mounted to which is attached a oord carrying n weight which tends constantly to rotate the shaft B clockwise as seen from its other end. Alternatively, if desired. the pnlley G may have fi'ictional engagement with the shaft B, so that althou h the pulley continuously rotates, the sha t can remain stationary when it is held as hereinafter described. At the other end of the shaft` is a pointer H which coperaties with an indicator-dial H.

At the sides of the disks C and E electroniagnets J and K are provided. The electromagnet J coperates with a vertically-situated armature J which is pivoted at its lower end to a pin J2 secured in the base and has a pallet Ja on that face of it which is toward the wheel C and an arm J which projects around to the other side of the wheel and is rovided on that side with a second pallet 5. The armature is kept toward the wheel by a spring L which is connected to a cross-bar L having engagement at one end with one of a series of notches J provided in the lower end of the armature-member J.

The other electro-magnet K is provided with an armature K having a allet K2 on that side which is toward the disk E. This armature is pivoted at its base and the lower end of the arn'iature-meniber is provided with notches K3 with one of which the bai' L1 has engagement so that the one spring L tends to keep both of these armatures up against their respective wheels C and E.

The means for energizing the electio-mag nets J and K may take any desired form and constitute no art of the present invention. It is already nown to operate an electroniagnet for e'ecting a change of light in a paratus of this kind, and such change is e ected by means of a contact which drops into notches at one edge of the negative film. For the purpose of this invention, two sucli contactdevices are provided cooperating with opposite sides of the film. The film is shown at M, Fig. 3, and the notches cominonly employed are indicated at M. The contact-device N is shown diagramiiiatically merely and comprises a roller N which, when it drops into the notch M1, causes its carrying-arm to come against a contact-piece N2, whereby the electrical circuit with the electro-magnet K is completed. At the other edge of the film, notches M2 are provided which cooperate with another contact-tle\ioe N whose construction and operation may be the saine as the contact-device N, but is iii 44`C' move as one member.

circuit with the electro-magnet J and closes this when it drops into a notch M2.

The operation of this apparatus is as follows The notches M are arranged as before in the film to effect a change of light at the moment any one notch passes the contactdevice. The lother notches M2 are arranged between any two of the notches M and are of such number :is to step the` stop for the selector E around to the point to which the selector will need to be advanced when the next notch M comes into operation. T he pointer il is shown in Fig. 1 as resting against the numeral 7 and it corresponds to the position occupied by the selector E on the rlieostat F, F. 1f now it is desired that the selector shall be moved at the next change over three contacts which will bring the pointer H to the figure 10, three notches` M2 are provided between the mitch M which is already` at, or has passed, the contact N and the'next. As soon as a notch M" comes opposite the contact N3 the circuit of the electromiignet J is closed. This drawsY the armature J toward the electroiiiagiiet and thus releases the pallet J3 from the teeth of the disk C, but brings the pallet J into the path of the next tooth. As the shaft B is always trying to turn clockwise. as viewed from the indicator end, the shaft will immediately advance with the disk C half a tooth space where it will be arrested by the pallet J", but directly the notch M2 hasl passed the contact-device N s, the electro-magnet J will be denergized and the spring L will cause the armature to return toward the wheel C, which will release the pallet J5 and bring the pallet Js a ain into position. By this means the disk C will complete another halftooth movement which will bring the pointer H from 7 to 8. The next two notches M2 cause the pointer H to advance respectively to t-hc figures 9 and 1U. but the selector 1*)1 so far has not moved. The stop C, however, has been moved away from the pin E on the disk E and as soon as the next notch M1 comes opposite thc contact-device N, the circuit. of the electro-magnet K is closed and the armature K is' drawn toward it so that its pallet K2 releases the disk E. No second pallet is required here as the disk E immediately advances under the tension of the spring D, which spring has been loaded by the advance of the sleeve C, until the projection El is arrested by the stop C.

he springr C serves as a buffer to take the shock of the projection E1 a ainst the stop C, but otherwise the sieeve C and the disk This movement of thdisk E carries the selector-ann E around to the position on the rheostat F, F. which corresponds t0 figure 10 of the indicator` and thus the requisite change. of light is effected.

It will be seen that 'any number of such changes may be brought about iu a length of film without any re-adjustment of the apparatus as it is only. necessary to pnt safticient notches M2 at the edge of the film between any two notches M to insure that theI proper change shall be etlected.

. In Fig; 4 another portion of film M is shown. which. instead `of being provided `witli'notches. is provided with slots M and M5. These slots effect the same purpose as the notches. the contact-devices being varied to suit them. for example. the film could pass overa roller "constituting one contactelement and the rollers of the contact-device would run upon the film instead of against the edge of it. so thatvwhen they dropinto -one or otherof the ynotches they would complete their respective circuits. a

By having a continuous notch such as M" the advance of the disk C or its equivalent may be effected by a continuous movement, in which case the second pallet J would be dispensed with and the disk would be allowed to turn under the action of the shaft B so. long as the pallet J-1 was held away from it, which would depend upon the length of thel slot M.

Again, the notches Ml and M2 need not,

be on different sides of the film as they could be on the same side. the contact-mem bers or the notches heilig so varied that only one contact-memher will operatively enter the notches Ml and the other will only operatively enter the notches M. lVhat I claim as my invention and desire to secure by Letters Patent is:- 1. In apparatus for exposing cinematograph positive films. the combination of a rotatable electric circuit-selector to control the source of light for the exposure. means tending always to angularly advance the said selector, means operated by the. |novement of the negative film to control the moment Vof advance of the selector. a stop to limit the angular movement of the. selector. means for automatically advancing the said stop intermittently, and means for controlling the intermittent. advance of said stop by the movement of the negatiye film, substantially as setforth.

2. In apparatus for exposing cinematoph positive films, the combination ot' a rotatable electric circuit-selector to control the source oflight for the exlmsure. means tending always to angularly advance the said selector, means operated by the movement of the negative film to control the moment of advance of the selector. a stop to limit the angular movement of the selector, means for automatically advancing the said stop intermittently. and means for controlling the intermittent advance of said stop b v the movement of the negative film. the control by the movement of the said film for the circuit-selector and its stop being so arranged that the stop is fu-ll'v advanced for the next position ot the selector before the controllingr means for the said selector iS operated to bring about the advance of the sclector. substantially as set forth.

3. In apparatus for exposing cinematograph positive films, the combination of a rotatable electric circuit-selector to cont-rol the source of light for the exposure, a stop to limit the angular movement of the said selector', means for automatically advancing the said stop intennittently, vieldingmeans operatively connecting the'stop with the Se lector in such manner that the latter always tends to follow the stop after it has been ad vanced. means for' controlling the intermittent advance of vsaid stop by the movement of the negative filln` and means operated by the. movement of thenegative film, to control the time of operation of said yielding means to advance the selector after the stop.

4. In apparatus for exposing cinematograph positive films the combination of a rotatable electric circuit-selector to control the source of light for the exposure. means tending always to angularly advance the said selector, a retaining catch for the selector, a member yieldingly pressed against the negativo film and operatively connected with the selector catch in such manner that when the member drops into a cut-away portion of the film it releases the catch. a stop to limit the angular movement of the selector, means for automatically advancing the said stop intermittently` and means for controlling intermittent advance of said Stop b v the. movement of the negative film, substantially as set forth.

5. In apparatus for exposing cinematograph positive films, the combination of a rotatable electric circuibselector to control the source of light for the exposure. means tending always to angular-l): advance the. said selector. a retaining catch for the selector` a member vieldingly pressed against the negativev fillm and operatively connected with the selector' catch in such manner that when the member drops into a cut-away portion of the film it releases thecatch. a stop to limit the angular movement of the Selector, means comprising an oscapement device for intermittently advancing the said stop. and a mem'ber vieldingly pressed against the negative, film and operatively connected with the .said escapemcnt device so that when the member drops into a cutaway portion of thc film it imparts a one step release to the escapement, substantially as set forth.

6. In apparatus for exposing cinematograph positive films. thc combination of a shaft. a rheostat whereof the points of contact are arranged around the shaft. an arm constituting a circuit-select0r carried by the shaft bu-t free to swing around the same over the contact points of the rheostat, a toothed member connected with the arm and having its toothed periphery concentric with the Shaft, a catch which engages the teeth of the toothed member and locks it against movement, means operated by the movement of the negative film and operatively connected with the catch to release the same when certain points of the film are reached, a springk made fast at one end relatively to the shaft and at the other end relatively to the circuit-selector arm, means always tending to rotate the shaft in the direction to load this spring, a toothed member fast on the Shaft, an escapement mechanism engaging the teeth of the latter member, means for controlling;r the movement of the escapement mechanism by the movement of the negative film, and a stop carried by the shaft and arranged to limit the angular movement of the selector arm but disposed in advance of the same so that when the catch holding the arm back is released it advances the distance permitted by the stop.

7. In apparatus for exposing cinematograph positive films, the combination 0f an electric circuit-selector in the form of an arm which moves over contact points disposed in a circular path, to control the source of light for the exposure, means tending always to angularly advance the said selector. means operated by the movement of the negative film'to control the moment of advance of the Selector, a sto-p movable in a circular path in advance of the Selector to limit the angular movement of the same, means for automatically advancing the said stop intermittently, and means for controllingI the intermittent advance of said stop by the movement of the negative film, substantially as set'forth.

In testimony whereof I alix my signature.

CECIL MILTON HEPWORTH. 

